Fix implementation plan issues from review

- Fix QualifiedIdentifier test to use non-keyword identifiers
- Fix scan_to_end to use correct remaining calculation from the start
- Extract ci_cmp to common.h, remove duplicates from keyword headers
- Add NAMES keyword to PostgreSQL keyword table
- Add missing tests for REPLACE, GRANT, REVOKE, LOCK, DEALLOCATE
- Add input_end() to Tokenizer from the start

Author: renecannao